[gentoo-user] HDD with too aggressive power management

[gentoo-user] HDD with too aggressive power management

[Nils Holland]

Hi folks,

I've got an Asus X7BJ-something laptop here that by default (i.e. when
installing plain Gentoo on it) seems to do too aggressive power
management for its hard drive. That is, already after only about five
seconds(!!) of inactivity, the HDD spins down. This is kind of insane
- you edit some small file, only half a minute later when you save it,
you have to wait for what feels like ages for your HDD to spin back up
and actually do something. ;-)

The first thing I tried was having a look at the BIOS to see if HDD
power management can be disable there. But no sir, no such option. Ok,
no problem I thought, and emerged "hdparm", which I have added to my
default runlevel, so that it gets executed with the arguments "-B 254
-S 0" upon each boot. That seems to fix it, HDD power management is
off and no more unwanted spindowns occur.

However, now comes the problem: It seems that whenever I change from
wall power to battery power (probably also vice versa, but I haven't
tested this often enough), the machine's HDD forgets about the
settings I've made using "hdparm" and starts spinning down right again
after only a few seconds of inactivity. That sucks.

Of course, manually executing "hdparm -B 254 -S 0 /dev/sda" after
unplugging the machine fixes the issue again. However, something more
"automated" would be prefered.

First thing, I'm wondering if the change in power management
parameters is actually caused by something at the OS level. I haven't
set up any such thing explicitly, so I believe that it's something the
machine just "does" outside of the OS's control. As it can be
overridden by executing "hdparm" manually, what I would need is probably
a place where I can hook in with a little shell script that gets
executed every time the system's power source changes, and does
nothing else than just execute "hdparm" with the appripriate
parameters. So much about the theory, but then I don't really have an
idea what I'd have to do to get a script to run every time the power
source changes. And that's why I'm writing this message, as any
suggestions that could point me into the right direction are very
welcome. ;-)

Greetings and thanks in advance,
Nils

-- 
Nils Holland * Ti Systems, Wunsorf-Luthe (Germany)
Powered by GNU/Linux since 1998

Re: [gentoo-user] HDD with too aggressive power management

[Paul Hartman]

On Mon, Jan 31, 2011 at 3:09 PM, Nils Holland <nhg@tisys.org> wrote:
> Of course, manually executing "hdparm -B 254 -S 0 /dev/sda" after
> unplugging the machine fixes the issue again. However, something more
> "automated" would be prefered.

I had the same problem. My solution was to edit /etc/conf.d/local and
add the command into the local_start() function (before the return):

local_start() {
        # This is a good place to load any misc programs
        # on startup (use &>/dev/null to hide output)

        hdparm -B 254 /dev/sd[abcdef]

        # We should always return 0
        return 0
}


and it automatically "fixes" my drives when I reboot.

Re: [gentoo-user] HDD with too aggressive power management

[Alan McKinnon]

Apparently, though unproven, at 23:09 on Monday 31 January 2011, Nils Holland 
did opine thusly:

> Hi folks,
> 
> I've got an Asus X7BJ-something laptop here that by default (i.e. when
> installing plain Gentoo on it) seems to do too aggressive power
> management for its hard drive. That is, already after only about five
> seconds(!!) of inactivity, the HDD spins down. This is kind of insane
> - you edit some small file, only half a minute later when you save it,
> you have to wait for what feels like ages for your HDD to spin back up
> and actually do something. ;-)
> 
> The first thing I tried was having a look at the BIOS to see if HDD
> power management can be disable there. But no sir, no such option. Ok,
> no problem I thought, and emerged "hdparm", which I have added to my
> default runlevel, so that it gets executed with the arguments "-B 254
> -S 0" upon each boot. That seems to fix it, HDD power management is
> off and no more unwanted spindowns occur.
> 
> However, now comes the problem: It seems that whenever I change from
> wall power to battery power (probably also vice versa, but I haven't
> tested this often enough), the machine's HDD forgets about the
> settings I've made using "hdparm" and starts spinning down right again
> after only a few seconds of inactivity. That sucks.

Running KDE with PowerDevil perhaps?






> 
> Of course, manually executing "hdparm -B 254 -S 0 /dev/sda" after
> unplugging the machine fixes the issue again. However, something more
> "automated" would be prefered.
> 
> First thing, I'm wondering if the change in power management
> parameters is actually caused by something at the OS level. I haven't
> set up any such thing explicitly, so I believe that it's something the
> machine just "does" outside of the OS's control. As it can be
> overridden by executing "hdparm" manually, what I would need is probably
> a place where I can hook in with a little shell script that gets
> executed every time the system's power source changes, and does
> nothing else than just execute "hdparm" with the appripriate
> parameters. So much about the theory, but then I don't really have an
> idea what I'd have to do to get a script to run every time the power
> source changes. And that's why I'm writing this message, as any
> suggestions that could point me into the right direction are very
> welcome. ;-)
> 
> Greetings and thanks in advance,
> Nils

-- 
alan dot mckinnon at gmail dot com

Re: [gentoo-user] HDD with too aggressive power management

[Iain Buchanan]

Hi,

On Mon, 2011-01-31 at 22:09 +0100, Nils Holland wrote:

> However, now comes the problem: It seems that whenever I change from
> wall power to battery power (probably also vice versa, but I haven't
> tested this often enough), the machine's HDD forgets about the
> settings I've made using "hdparm" and starts spinning down right again
> after only a few seconds of inactivity. That sucks.

frustrating indeed!  It could be a number of things: gnome, acpi, and/or
bios making the changes automatically.

My preference would be to fix it in acpid since it will work independent
of the window manager or even X.

emerge acpid, then edit /etc/acpi/default.sh similarly (sorry about the
tabs/spaces):

...
	ac_adapter)
		case "$value" in
          *0)
              # code for unplugging the power
              echo conservative > /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor
              echo conservative > /sys/devices/system/cpu/cpu1/cpufreq/scaling_governor
              ;;
          *1)
              # code for plugging in the power
              echo performance > /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor
              echo performance > /sys/devices/system/cpu/cpu1/cpufreq/scaling_governor
              ;;
...

Change (or add) your hdparm commands as required.  You could have a
different spin-down setting for power and battery if you wish.

You'll still have to change the setting after booting, since acpi events
usually aren't triggered then.  Use local_start() as Paul suggested.  If
you suspend you may even have to do it after resuming as well.  Note
that if you use different spin down times you'll need to detect the
state of AC before running the hdparm command.  Something like this
in /usr/local/bin/ should do:

#!/bin/sh
if ( awk '{print $2}' /proc/acpi/ac_adapter/AC/state | grep on-line ); then
    # AC adaptor is on-line!
    echo performance > /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor
    echo performance > /sys/devices/system/cpu/cpu1/cpufreq/scaling_governor
else
    # AC adaptor is off-line!
    echo conservative > /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor
    echo conservative > /sys/devices/system/cpu/cpu1/cpufreq/scaling_governor
fi

then call that script from local_start().

HTH!
-- 
Iain Buchanan <iaindb at netspace dot net dot au>

I can write better than anybody who can write faster, and I can write
faster than anybody who can write better.
		-- A.J. Liebling

Re: [gentoo-user] HDD with too aggressive power management

[Nils Holland]

On 08:38 Tue 01 Feb     , Iain Buchanan wrote:
> Hi,
> 
> On Mon, 2011-01-31 at 22:09 +0100, Nils Holland wrote:
> 
> > However, now comes the problem: It seems that whenever I change from
> > wall power to battery power (probably also vice versa, but I haven't
> > tested this often enough), the machine's HDD forgets about the
> > settings I've made using "hdparm" and starts spinning down right again
> > after only a few seconds of inactivity. That sucks.
> 
> frustrating indeed!  It could be a number of things: gnome, acpi, and/or
> bios making the changes automatically.
> 
> My preference would be to fix it in acpid since it will work independent
> of the window manager or even X.
> 
> emerge acpid, then edit /etc/acpi/default.sh similarly (sorry about the
> tabs/spaces):
>
> [...] 

Hi Iain and everyone who replied,

thanks for all of your suggestions! In fact, I've noticed that GNOME
and other desktop environments seem to contain grephical interfaces
for setting the HDD to spin down automatically and already suspected
such a piece of software unwantedly being responsible for the behavior
I'm seeing. But I guess I can actually rule that out: I'm not using
any such desktop environment, but am actually using only the "awesome"
wm as my window manager. Furthermore, I don't use an X Display manager
but boot up in console-only mode and start X only when needed via
"startx". Therefore, I can rule out GNOME, KDE, etc. being
responsible, and as for the rest of the stuff I've installed, I've
choosen it rather carefully and certainly didn't installing anything
power-management-like.

I guess it's probably the way this machine "works", and feel that the
reference to acpid sounds like a very promising way to fixing this. As
such, thanks to everyone who pointed me into that direction - I'll
have a look and see if it works!

Greetings and thanks again,
Nils


-- 
Nils Holland * Ti Systems, Wunsorf-Luthe (Germany)
Powered by GNU/Linux since 1998

Re: [gentoo-user] HDD with too aggressive power management

[Nils Holland]

On 22:08 Tue 01 Feb     , Nils Holland wrote:
 
> I guess it's probably the way this machine "works", and feel that the
> reference to acpid sounds like a very promising way to fixing this. As
> such, thanks to everyone who pointed me into that direction - I'll
> have a look and see if it works!

Replying to myself here, but wanted to give everybody who pointed my
in the acpid direction yesterday some feedback: I emerged acpid
yesterday, had a look at your examples, studied the man page a bit and
set it up. And well, I've explicitly switched between wall power and
battery power more often than I would normally do, with the result
that I can now say that the suggested solution works really well!

Thanks again and greetings,
Nils


-- 
Nils Holland * Ti Systems, Wunsorf-Luthe (Germany)
Powered by GNU/Linux since 1998